Power steering-gear.



E. P. ROBINSON.

POWER STEERING GEAR.

APPLIoATIoN FILED MAY a, 191s.

'1,086,465, l l Patented Feb10, 1914.

EDWARD P. ROBINSON, 0F MALDEN, MASSACHUSETTS.

POWER STEERING-GEAR.

ibamos.

Specification of Letters Patent.

Patented Feb. 10, 1914.

Application led May 9, 1913. Serial No. 766,489.

To all whom it may concern:

Be it known that I, EDWARD P. ROBINSON, a citizen of the `United lStates, residing in Malden,- in the county of Middlesex and State of Massachusetts, have invented an Improvement in Power Steering-Gear, of which the following description, in connection `with 'the accompanying drawings, is a specification, like letters on the drawings representing like parts.

The present invention relates to a power steering gear, and is embodiedin a steering gear in which the power is used as a supplement to the regular hand steering gear, the arrangement being such that the appliances through which the power is utilizcd, do not interfere with hand steering in case it is, desirable not to use the power at all. Furthermore, the arrangement is such that the power is not called upon at all until the rudder has been moved a short distance, say five or ten degrees, in either direction from mid-position, so that when the ship is on an yeven course, the steering is done entirely by hand, and the power element is saved. At the same time, if the rudder is to be thrown toward one extreme or the other, to chanoe the ships course, the power is automatical supplied.

In accordance wih the invention, the tiller rod. which is a longitudinally movable rod connected in any suitable way with the rudder, is directly controlled by the hand steering wheel the longitudinal movement beingproduced by a worm or screw gear, or any equivalent cam or gear connection through which the rotary movement of the wheel is converted. The said lon itudinally movable member is connected wi h a piston in a power cylinder, the ports at opposite ends of said cylinder being controlled in any suitable way, as by the ordinary D-valve, and the arrangement is such thatthe said D-valve is shifted in its position to admit pressure to one side of the piston or the other in response to the first movement of the steering wheel in one direction orthe other from'thc mid-position. rl`he pressure, however, is not admitted to the cylinder during this movement, and the rudder is moved for a short distance through the action of the steering wheel alone. A further movement of the steering wheel, however, and consequent further movement ofthe rudder, acts upon a stop valve leading to the steam chest of the power cylinder, so' as to open the said stop valve and admit pres sure. This pressure acting on the piston tends to force the same in the direction in which it is moved by the steering wheel, the movement, however, being at all times under the control of the wheel, although the work of moving the rudder is mainly performed by power. f

Figure 1 is a side elevation, partly in sec tion, of a steering gear embodying the invention; Fig. 2 is a plan View of the same, partly in section, with-the steering wheel connection omitted; and Fig. 3 is an en larged sectional detail.`

In the construction shown, the connection between the operating mechanism and the rudder consists of a longitudinally movable rod l provided with a serewthread 2, or equivalent motion transmitting gear, extending through a gear 3 having .a corresponding internal thread to cooperate with the thread 2. The said gear 3 is mounted in a bearing in a stationary frame 4, and is in mesh with the gear 5 adapted to be rotated by the steering wheel 6. It is obvious, therefore, that the rot-ation of the gear 5 acting through the (gear 3 will produce the necessary longitu inal movement of the rod l directly through the action of the wheel 6, so that the steering can be done partly or wholly by hand.

lln the following` description the rod 1 will be referred to as the tiller rod with the understanding that any equivalent means may be employed to transmit to the rudder the movements controlled or produced by the wheel.

When a ship is holding a substantially straight course, the steering can be better done by hand, as no great power is necessary to keep .the ship on a straight course. When, however, the ships course is to be changed to any extent, the resistance to the movement of the rudder becomes greater, and it is desirable to apply power to perform the actual work, under the guidance of the wheel.

In accordance with the invention, power is directly applied to the tiller rod 1, and

-in the construction shown the said tiller ro'd is connected with a piston 7, in a cylinder 8, so that steam or other fluid pressure can be admitted to either end of the cylinder, thereby tending to drive the tiller rod 1 in one direction or the other.

The admission of the pressure is con- 60 groove 28.

1o on the hub of the gear 5. The hub 14 is provided with lugs or projections 15, which straddle a lug or projection 16 on the gear 5,

the space between the said projection being greater than the width of the lug 1G, so

15 that there is some lost motion between the hub 14 and the gear 5 before the latteris caused to travel with the wheel G. This preliminary movement of the hub 14 causes the longitudinal movement of the D valve 9, the

240 rod being connected with a forked lever 17 pivoted at 18 and having projections 19 which enter an annular channel 20 in a yoke 21. The said yoke 21 is splined on the hub of the gear 5, and is caused to move longitudinallyv through the agency of inclined cam grooves 22 formed in the hub 14, so

that as the said hub 14 is turned, the valve -9 will be moved in one direction or the other in accordance with the direction of movement of the steering-wheel 6. The yoke 21 is prevented from turning during this part of the operation owing to its spline connecft-ion with the hub of the gear 5, which remains stationary until it is picked up by one of the projections 15, after which all the parts can rotate together, owing to the tongue and groove. connection between the forked lever 17 and the member 21. Each time, therefore, that the wheel is turned* from mid-position, the D-valve is carried to the right position to admit pressure to assist in the steering operation, the admission of the pressure, however, being further controlled by a stop-valve 23. In the construc- L tion shown, this stop valve is normally held closed by means of a spring 24, and is adapted to be opened through the agency of an elbow lever 25 pivoted at 26, and having an extended portion 27 provided with a cam This cam groove is engaged with a projection 29 movable with the tiller rod '1, and being herein shown as supported on a cross-head 30 which supports the tiller rod on the guides 31. During the first part of the movement of the rudder in either direction, the tiller rod 1 is moved entirely by hand power, but, after it has been moved a certain distance in either direction, one or theother of the inclined portions of the cam groove 28 Will be engaged by the projection 29, thus lifting the cam end of the elbow lever 25 and causing the other end thereof to engage and open the valve 23. Pressure is thus admitted at one side or the other of the piston 7, so that in the further elbow lever 25 will drop to the position shown in Fig. 1, thereby allowing the pressure valve 23 to close and cut oil' the power. In this construction, the addition of the poirier-operated piston does not add materially to the labor of steering by hand, so

that if it is desired to dispense with the power entirely, it is necessary only to disconnect the means for opening the stop valve 23, or shut ofl' the pressure altogether. Furthermore, even when the stop valve is in its operative position, the greater art'of the steering, when the ship is fgllowing a straight course, is done by hand, although the power is immediately and automatically available when the rudder is thrown beyond the limits of easy hand operation.

The pitch of the screw, or equivalenttransmitting gear between the steering wheel and the rod is so calculated as to afford very little resistance to the movement of the tiller-rod when acted upon by the motor while the wheel is being turned, but is sufficiently steep to resist being turned by the power. It is to be noted, however, in this connection, that if the power acting on the rod is suiiicient to actually turn the gear which is connected through the lugs 15 and 16 with the steering wheel causing it to travel faster than the wheel, such independent movement will close the valve before the gear picks up the wheel, through the lost motion connection; so that there is no danger of losing control of the wheel, as might otherwise happen.

What I claim is:

l. In a power steering gear, the combination with a` longitudinally movable tiller rod; of a rotary member geared to said rod to produce the longitudinal movement thereof; a steering wheel having a lost motion connection with said rota-ry member; a motor directly connected with said tiller rod to act in either direction thereon; a reversing valve for said motor; and means operated by the steering Wheel during the movement thereof relative to the gear for operating said controlling valve.

2. In a power steering gear, the combination with a longitudinally movable tiller rod; of a rotary member geared to said rod to produce a longitudinal movement thereof; a steering Wheel having a lost motion connection with said rotary member; a motor directly connected with said tiller rod to act said rod; a reversing valve for said motor;

a steering wheel connected to said rod to produce a longitudinal movement thereof, there being a lost motion connection between said steering wheel and the gearing; a reversing valve for said motor; means for operating'said reversing valve in response to the movement of the wheel; and a stopvalve for admitting pressure to the motor operated in response to a longitudinal movement of the tiller rod in either direction.

4. In 'a steering gear, the combination with a cylinder having a piston directly connected with a longitudinally movable tiller rod; of a reversing valve for said cylinder; a rotary gearing also adapted to produce a longitudinal movement of said tiller rod; a longitudinally movable actuating member for said reversing valve having a splined connection with said rotary gearing; a rotary cam operated by the steering wheel and having a lost motion connection with said gearing; and means whereby the rotation of said cam causes the longitudinal movement ofthe valve actuating member, substantially as described.

5. .In a Asteering gear, the combination with a tiller-rod; of fa pressure-operatedl piston directly connected with said rod; a cylinder for said piston; a D-valve controlling the ports of said cylinder; a stop-valve controlling the admission ofpressure to said cylinder; a steering wheel; means oper- Y ated by .said steering wheel for controlling member adapted to operate therudder and' said D-valve; and means operated by the longitudinal movement of the tiller rod for controlling tbe said stop. valve.

6. In a steering gear, a pressure operated being permanently connected therewith; a steering wheel having a permanent lostmotion connection with-'the rudder; a reversing valve to control the pressureI which operates on the piston; and means whereby sald reversing valve is operated by the steer..

tion with a rudder, of a rotary member connected to said rudder to produce a movement thereof; a steering wheel having a lost-motion connection with said rotary member; a motor permanently connected with the rudder to move said rudderin either direction; a reversing valve for said motor; and means operated by the steering wheel during the movement thereof relative to said rotary member for operating said reversing valve.

8. In a power steering gear, the combination with'a rudder, of a rotary member connected to said rudder to produce a movement thereof; a steeringV wheelhaving a lost-mo tion connection with said rotary member; 'a motor permanently connected with the rudder to move said rudder in either direc- 'tion; a reversing valve for said motor;

means'operated by the steering wheel during, the movement thereof relative to said rotary member oroperating said reversing valve; an independent valve for admitting pressure to the motor; and means operated l"oy the steering mechanism for opening said independent valve after said rudder has moved a pre-determined distance in either direction. l

9. The combination with a steering gear, of a singlemanually operated wheel or tiller permanently and operatively connected with said gear whereby 'sa-id gear can be positively moved by said wheel;` and a motor also`permanently and operativelyconnected with said gear to furnish power in addition to the manual power applied directly to the wheel.

'10. The combination with a steering gear, of a single manually operated wheel or tiller permanently and operatively connected with said gear;- a motoralso permanently and operatively connected with said gear; and means for. controlling the source of power which operates said motor, said means being actuatedl automatically after the rudder has been movedY a pre-determined distance from mid-position.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses:

EDWARD P. ROBINSON.

Witnesses-z JAs.- J. MALONEY, W.l E.- CovENLY. 

